Fast electrochemical redox kinetics of two-dimensional TiO2/Ti3C2Tx (MXene) heterostructure for high-performance lithium-ion capacitor

•TiO2/Ti3C2Tx heterostructure was first synthesized through a facile and cost-effective aqueous self-assembly.•TiO2/Ti3C2Tx heterostructure demonstrates enhanced specific capacity, outstanding rate capability and excellent cyclic stability.•TiO2/Ti3C2Tx exhibits pseudocapacitive behavior which endows it with fast lithium storage kinetics.•TiO2/Ti3C2Tx//CPC LIC obtains a wide operating voltage range and delivers an exceptionally high energy density (129.4 Wh·kg−1).